Heating, ventilation and air-conditioning unit for the passenger compartment of a motor vehicle

ABSTRACT

A unit includes  
     a support structure ( 2 ) with first and second intakes ( 3, 4 ) defined therein for air from inside and outside the compartment respectively, and at least one outlet ( 5 - 7 ) for conveying air treated in the unit ( 1 ) into the passenger compartment,  
     a fan ( 10 ), arranged downstream of the said intakes ( 3, 4 ) for setting up a flow of air through the structure ( 2 ) between one of the said intakes ( 3, 4 ) and at least one outlet ( 5 - 7 );  
     first and second heat exchangers ( 13, 14 ) arranged downstream of the fan ( 10 ) for respectively cooling and heating the flow of air set up by the fan ( 10 );  
     an air heater ( 30 ) integrated into the support structure ( 2 ), including a fuel burner ( 31 ) and having an intake ( 32 ) for combustion air which is in communication with the second intake ( 4 ) of the unit ( 1 ) and an outlet ( 33 ) for evacuation of the combustion gases; the air heater ( 30 ) being arranged so that it can heat a flow of air set up by the fan ( 10 ) between a first intake ( 3 ) and at least one outlet ( 5 - 7 ) of the unit ( 1 ); and  
     an electronic control unit (ECU) connected to sensors ( 18, 19 ) and actuators ( 15 - 17; . . .  ) associated with the unit ( 1 ), to a control device operable by a user and to the said burner ( 31 ), and arranged to control operation of the unit ( 1 ) of the burner ( 31 ) in predetermined modes.

DESCRIPTION

[0001] The present invention relates to a heating, ventilation and air-conditioning unit for the passenger compartment of a motor vehicle.

[0002] More specifically, the invention relates to a unit which includes

[0003] a support structure with at least first and second intakes formed therein for air from inside and outside the compartment respectively, and at least one outlet for air treated in the unit to enter the compartment;

[0004] a fan, arranged downstream of the said intakes, for setting up a flow of air between at least one of the said intakes and the said at least one outlet;

[0005] first and second heat exchange means, arranged in the said structure downstream of the fan, for respectively cooling and heating the airflow set up by the fan; and

[0006] an electronic processing and control unit connected to sensor devices and actuator devices of the unit and to control means operable by a user, and provided to control operation of the unit according to predetermined instructions.

[0007] In addition to a heating, ventilation and air-conditioning unit of this type, some motor vehicles, especially freight vehicles and top of the range motor cars, also have additional heaters such as so-called parking heaters, which enable the passenger compartment to be warmed before the vehicle has been started.

[0008] Such extra heaters can be of a type in which a fuel burner directly heats air which is recirculated through the compartment, or of a type which heats a flow of engine cooling fluid which then heats the air in the passenger compartment by means of a heat exchanger.

[0009] In either case, extra heaters currently in use include their own electric fan and an electronic control unit which controls their operation by means of one or more sensors.

[0010] Arrangements used in the prior art have the disadvantage of being fairly expensive which is a barrier to their application in motor cars other than luxury ranges.

[0011] The object of the present invention is to provide an arrangement which makes it feasible to provide an extra heater both simply and economically in any motor vehicle fitted with a heating, ventilation and air-conditioning unit.

[0012] This and other objects are achieved according to the invention by providing a unit of the type described above, characterised in that

[0013] it also includes an air-heater, integrated into the aforesaid support structure and including a fuel burner, and having a combustion air intake in communication with the said first and/or second intake of the unit and an outlet for evacuating combustion gases; the air heater being arranged in the support structure in such a way that it can heat a flow of air set up by the fan between the said first intake and the said at least one outlet;

[0014] and in that the electronic processing and control unit is also connected to the said burner and is operable to control the operation thereof according to predetermined instructions.

[0015] Further characteristics and advantages of the invention will become apparent from the detailed description, provided purely by way of non-limitative example with reference to the appended drawing, which is a schematic illustration of a heating, ventilation and air-conditioning unit according to the invention.

[0016] This unit, generally indicated 1 in the drawings, includes a support structure 2 with first and second intakes 3, 4 formed therein for air from respectively inside and outside the passenger compartment of a motor vehicle.

[0017] The structure 2 of the unit 1 also has a plurality of outlets 5, 6 and 7 for air treated by the unit to flow into the passenger compartment. In the embodiment illustrated schematically by way of example, the outlet 5 is provided to direct a flow of air towards the inside of the windscreen, the outlet 6 is intended to be connected with a plurality of ventilation nozzles in the upper-middle portion of the compartment, while the outlet 7 is intended to direct a flow of treated air into the bottom portion of the compartment.

[0018] Respective flaps, indicated 5 a, 6 a and 7 a, are associated with the outlets 5, 6 and 7 for controlling the flow of air through each outlet.

[0019] An additional flap 8 a makes it possible selectively to connect either the internal air intake 3 or the external air intake 4 with a region 9 of the structure 2 where an electric fan 10, constituted by rotatable blades 11 and an electric operating motor 12, is arranged.

[0020] In operation, the electric fan 10 sets up a flow of air through the structure 2 of the unit 1 between either the intake 3 or the intake 4 and one or more of the outlets 5-7.

[0021] First and second heat exchangers, indicated 13 and 14, are arranged in the structure 2 of the unit, downstream of the electric fan 10.

[0022] It is convenient if the heat exchanger 13 consists of the evaporator of a cooling unit known per se, which includes a motor-driven compressor 15.

[0023] It is also convenient if the heat exchanger 14 is of a liquid/air type, suitable to be fitted into the cooling circuit of the combustion engine of the vehicle in such a way that it is controllable by a solenoid valve 16.

[0024] An additional, motor-controlled flap, indicated 17 in the drawing, is also provided, in a position enabling it to control connection of the outlets 5-7 to the evaporator 13 and the heater 14.

[0025] An electronic processing and control unit, indicated ECU, is constituted by a microprocessor, for example,

[0026] The unit ECU is arranged, in a manner known per se, to control operation of the unit 1 according to predetermined instructions. In particular, this unit is operable to control operation of the electric fan 10, the position of the flaps 8 a and 17, operation of the compressor 15 and the solenoid valve 16, all in dependence on signals received from sensors associated with the heating unit, such as temperature sensors 18 and 19 as well as from a control device 20 operable by a user in order to achieve a desired climate in the passenger compartment.

[0027] A heating, ventilation and air-conditioning unit 1 also includes an air heater 30, integrated into the support structure 2. This heater comprises a fuel burner 31 and has an intake 32 for combustion air, which is in communication with the intake 4 of the unit, and an outlet for the evacuation of combustion gases. Fuel is fed to the burner 31 by an electric pump 34.

[0028] The heater 30 is positioned so that it can warm a flow of air set up by the electric fan 10 and which enters the heater 30 through an intake 35, leaving through an outlet duct 36 which opens upstream of the outlets 5-7.

[0029] A temperature sensor, indicated 37, measures the temperature of the air heated by the heater.

[0030] The burner 31 and the electric pump 34 supplying the fuel are controlled by the processing and control unit ECU, to which the output of the sensor 37 is also connected.

[0031] The electronic unit ECU is also operable to control operation of the heater 30 integrated into the unit 1, in accordance with predetermined instructions and strategies.

[0032] A convenient synergy operates in the heating, ventilation and air-conditioning unit described above, since the electric fan 10 and the processing and control unit ECU of the unit 1 are also used to operate the air heater 30.

[0033] The arrangement of the invention also offers clear advantages with regard to installation.

[0034] By way of example, the drawing shows the heater 30 arranged next to the evaporator 13. This arrangement is not obligatory, however, since the heater could also be arranged next to the heater 14 or in any position within the structure 2 judged to be structurally appropriate.

[0035] In a variant of the invention, the heater 30 could be designed so that it could also heat the cooling fluid of the vehicle's internal combustion engine, thereby also preliminarily warming the said engine as well as heating the passenger compartment, which would be useful in cold weather.

[0036] Naturally, the principle of the invention remaining unchanged, embodiments and manufacturing details can be varied widely from those described and illustrated here purely by way of non-limitative example, without departing thereby from the scope of the invention, as claimed in the appended claims. 

1. A heating, ventilation and air-conditioning unit for the passenger compartment of a motor vehicle, including a support structure in which at least first and second intakes are defined for air from inside or outside the passenger compartment respectively, and at least one outlet for delivering air treated in the unit into the passenger compartment; a controlled fan, arranged in the structure downstream of the said intakes for setting up a flow of air through the structure between at least one of the intakes and the said at least one outlet; first and second heat exchange means arranged in the structure downstream of the fan and operable respectively to cool and heat the flow of air set up by the fan; an electronic processing and control unit connected to sensor devices and to actuator devices associated with the unit and also to control means operable by a user and provided to control operation of the unit according to predetermined mode; and an air heater, integrated into the support structure, including a fuel burner and having an intake for combustion air, in communication with the said second intake of the unit and an outlet for the evacuation of combustion gases; the air heater being positioned so that it can heat a flow of air set up by the said fan between the first intake and the said at least one outlet of the unit; the electronic processing and control unit being also connected to said burner and being arranged to control operation thereof in predetermined modes.
 2. A heating, ventilation and air-conditioning unit according to claim 1, in which the said air heater includes means for supplying fuel to the said burner and in which the processing and control unit is arranged to control the said means according to predetermined instructions.
 3. A heating, ventilation and air-conditioning unit according to claims 1, including temperature measuring means associated with the air heater, for measuring the temperature of the heated air, said temperature measuring means being connected to the processing and control unit.
 4. A heating, ventilation and air-conditioning unit according to claim 1, in which the said heater is also operable to heat the cooling fluid of the internal combustion engine associated with the vehicle. 